The present invention generally relates to surgical instruments used in surgical procedures, and more particularly to an improved handle that permits various instruments to be releaseably attached for quicker and easier interchange.
The development of newer minimally invasive surgical techniques, such as laparoscopic surgery, have allowed surgeons to successfully perform numerous operative procedures in many instances which in the past required the need for large surgical incisions. In this newer procedure, one or several very small incisions are made in the patient through which various surgical instruments may be used to perform the required surgical procedure. Minimally invasive surgery offers benefits which include creating less trauma to the patient, reducing the risk of post-operative infections, and allowing speedier recovery than conventional surgery with its larger incisions.
Trocars are commonly used in minimally invasive surgeries. They generally consist of a hollow cannula (tube) and an obturator (bladed or pointed piercing device) which are used, in combination, to make a small portal into a patient. The obturator is designed to slide inside the cannula to create a single unit that may be used to penetrate a small incision that has been previously made by a surgeon. Once the trocar has penetrated the patient""s body cavity, the obturator is withdrawn while leaving the cannula in position. Various surgical instruments can then be worked through the cannula to perform whatever surgical technique is required.
Trocars are particularly useful in many types of surgery in which a small incision will permit the required surgical procedure to be completed. One such application is in maxillofacial surgery where bone fractures occurring in the maxilla or mandible are stabilized by bone screws and/or bone plates. In this trocar application, drill guides can be inserted through the cannula which allow the surgeon to pre-drill holes in the bone for receiving bone screws. Trocars can also be used with soft tissue retractors, such as cheek retractors which are employed to hold the tissue away from the surgical site so that it does not interfere with fixation of the facial fracture.
The cannula may be fastened or secured to a handle of some type. This helps the surgeon control the trocar and facilitates the process of both making the initial incision accurately and subsequently working with various instruments in a manner which reduces the chance of the cannula being pulled from the patient""s body cavity prematurely.
Handles of the past have typically employed various approaches for coupling the cannula to the handle. For example, cannulas were often attached in a permanent manner to the handle such as by welding. Semi-permanent type couplings have also been used such as threading the cannula head to the handle, or providing set screws to hold both parts together. U.S. Pat. No. 5,755,721 to Hearn discloses another semi-permanent type of coupling wherein a retaining ring with an internal depression around its circumference is provided that mates with a spring and ball detent on a surgical instrument. The instrument is pushed into the retaining ring until the detent is seated in the depression.
The handle designs of the past have several drawbacks. The permanent type attachment does not allow the surgeon to interchange different kinds or sizes of surgical instruments. This reduced flexibility for the surgeon and increased prices for each trocar unit which must contain both a handle and permanently affixed cannula. Overall inventory costs are thereby also increased.
Although the semi-permanent type couplings offer interchangeability of surgical instruments, they too have been problematic. Using set screws or threaded coupling of the cannula to the handle makes changing instruments cumbersome, especially when it must be done during the exigencies of a surgical procedure. While offering improvement, the coupling described in the Hearn patent does not positively lock the cannula to the handle in a manner that requires the surgeon to unlock the cannula from the handle.
Accordingly, there is a need for a handle which allows for improved releasability and interchangeability of various surgical instruments with the handle while overcoming the problems associated with the foregoing prior art devices.
The invention is generally directed to a handle and system of surgical tools which can be designed specifically to be compatible and interchangeable with the handle.
In accordance with one embodiment, the handle is comprised of a grasping portion and a handle lock assembly. The grasping portion is used by the surgeon to hold and control the handle. The handle lock assembly comprises a body with a top and a bottom, and further includes a retractable slider pin which secures a surgical instrument to the handle.
In another embodiment, the lock assembly body includes an opening disposed in the body through which surgical instruments are inserted. The opening, which is preferably circular in one embodiment, extends from the top to the bottom of the lock assembly body creating an opening passing completely through the body. The retractable slider pin is movable from an extended position in which the pin protrudes into the opening and secures the surgical instrument to the handle, to a retracted position in which the pin is withdrawn from the opening.
The slider pin may be connected to a handle slider which is preferably a rectangular or square block in configuration, but is not limited to those shapes. The slider pin may be integrally connected with the handle slider such as by welding or the slider pin and handle slider may be formed as an integral unit. Also preferably, the handle slider is slidably mounted in a cavity or other opening provided in the body of the handle lock assembly. Alternatively, the handle slider may be mounted on the exterior of the handle lock assembly which is a matter of design choice.
In one embodiment, the handle lock assembly of the handle includes at least one handle release. The handle release is used to move the retractable slider pin from the extended position to the retracted position as discussed above. The handle release is connected to the handle slider which is connected to the slider pin, thereby moving the pin.
In accordance with another embodiment, at least one biasing member is provided which biases the slider pin toward its extended position. Preferably, the biasing member is a helical spring. In one embodiment, the biasing member may be held by a recess provided in the handle slider. The handle lock assembly may be attached to the grasping portion of the handle by welding. The handle including the grasping portion and handle lock assembly may be made of stainless steel, however, it may be made of any material suitable for the intended application. The grasping portion of the handle may be hollow which reduces the cost and weight of the handle.
In accordance with one embodiment, the surgical instrument that may be used with the handle of the invention is a cannula or trocar assembly. The cannula, or different instrument as the case may be, may include indentations which are designed to engage the retractable slider pin thereby securing the cannula to the handle. Preferably, the cannula or different instrument may further include additional depressions which may be used to secure at least one additional surgical device to the handle. In one embodiment, a soft tissue retractor is an additional device that may be attached to the handle. Preferably, the cannula or different instrument, and additional devices that may be attached to the handle may be made of stainless steel, however, they may be made of any material suitable for the intended application. The cannula or different instrument may further include a body portion and a head portion, and preferably where these two portions are of different size diameters, an inclined ramp may be included between the two portions to facilitate insertion of the cannula into the handle as discussed below. The cannula or different surgical instrument may further comprise a knob connected to the cannula or different instrument for grasping and rotating the cannula or different instrument. At least one slot may be provided in the knob for mating and engaging with at least one tab provided on a surgical instrument intended to be inserted through the cannula or different surgical instrument secured to the handle to prevent rotation of the inserted instrument in the cannula or different instrument. An obturator or a drill guide which are well known in the art may be such an instrument provided with at least one tab which mates with the at least one slot in the knob of the cannula or different instrument.
In another embodiment, the handle lock assembly body of the handle may include a transition portion between the handle lock assembly and the grasping portion. The grasping portion preferably may be angularly displaced, preferably about 30 degrees, from the plane of the top of the handle lock assembly.
A handle lock system for performing a surgical procedure is also provided. The system may comprise a handle which has a grasping portion and handle lock assembly. The lock assembly comprises a body with a top and a bottom, and a retractable slider pin. The system further may include a cannula or different instrument having indentations to engage the slider pin thereby securing the cannula to the handle. In one embodiment, the handle lock system may further include additional depressions for securing an additional surgical instrument to the trocar handle. Preferably, the additional surgical instrument may be a soft tissue retractor.
A method of interchangeably using surgical instruments in a handle lock assembly, and a trocar specifically, is also provided, which may comprise the steps of: (a) providing a handle, the handle having a grasping portion and a lock assembly, the lock assembly comprising a body with a top and a bottom, a retractable slider pin, and a passageway disposed in the body wherein the surgical instruments are inserted for securing to the handle, the retractable slider pin being movable from an extended position in which the pin protrudes into the passageway to a retracted position in which the pin is withdrawn from the passageway; (b) providing a cannula having indentations to engage the retractable slider pin thereby securing the cannula to the handle; (c) inserting the cannula in the handle; (d) locking the cannula to the handle by engaging the retractable pin in one of the indentations; (e) retracting the retractable pin from the extended position to the retracted position; and (f) removing the cannula from the handle. The method may comprise inserting a different surgical instrument having indentations into the passageway other than a cannula. The method may further include inserting an obturator into the cannula.
In another embodiment of the method, locking the cannula or different surgical instrument to the handle may further include the steps of withdrawing the slider pin from the passageway to the retracted position by a user and inserting the cannula or different instrument into the passageway before the slider pin engages one of the indentations. The method may also further include the step of rotating the cannula or different instrument to align the indentations and sliding pin to lock the cannula or different instrument to the handle.
It will be appreciated by one skilled in the art that the invention is particularly useful for maxillofacial surgical procedures. However, use of the invention is not limited to maxillofacial surgery alone and the invention may be used with and in any type of medical or dental procedure where it is desirable to releaseably attach medical or dental instruments to a handle.